fix(datepicker): performance issues when huge min/max dates

Fixes ng-bootstrap#3338
maxokorokov · Sep 6, 2019 · d26a65e · d26a65e
1 parent 2bd3abc
commit d26a65e
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Showing 2 changed files with 12 additions and 6 deletions.
diff --git a/src/datepicker/datepicker-tools.spec.ts b/src/datepicker/datepicker-tools.spec.ts
@@ -566,17 +566,17 @@ describe(`datepicker-tools`, () => {
     it(`should generate years correctly`, () => {
       // both 'min' and 'max' are set
       test(new NgbDate(2017, 1, 1), new NgbDate(2018, 1, 1), new NgbDate(2019, 1, 1), range(2017, 2019));
-      test(new NgbDate(2000, 1, 1), new NgbDate(2018, 1, 1), new NgbDate(3000, 1, 1), range(2000, 3000));
+      test(new NgbDate(1000, 1, 1), new NgbDate(2018, 1, 1), new NgbDate(3000, 1, 1), range(1518, 2518));
       test(new NgbDate(2018, 1, 1), new NgbDate(2018, 1, 1), new NgbDate(2018, 1, 1), [2018]);
 
       // 'min' is not set
       test(null, new NgbDate(2018, 1, 1), new NgbDate(2019, 1, 1), range(2008, 2019));
-      test(null, new NgbDate(2018, 1, 1), new NgbDate(3000, 1, 1), range(2008, 3000));
+      test(null, new NgbDate(2018, 1, 1), new NgbDate(3000, 1, 1), range(2008, 2518));
       test(null, new NgbDate(2018, 1, 1), new NgbDate(2018, 1, 1), range(2008, 2018));
 
       // 'max' is not set
       test(new NgbDate(2017, 1, 1), new NgbDate(2018, 1, 1), null, range(2017, 2028));
-      test(new NgbDate(2000, 1, 1), new NgbDate(2018, 1, 1), null, range(2000, 2028));
+      test(new NgbDate(1000, 1, 1), new NgbDate(2018, 1, 1), null, range(1518, 2028));
       test(new NgbDate(2018, 1, 1), new NgbDate(2018, 1, 1), null, range(2018, 2028));
 
       // both are not set

diff --git a/src/datepicker/datepicker-tools.ts b/src/datepicker/datepicker-tools.ts
@@ -71,10 +71,16 @@ export function generateSelectBoxYears(date: NgbDate, minDate: NgbDate, maxDate:
     return [];
   }
 
-  const start = minDate && minDate.year || date.year - 10;
-  const end = maxDate && maxDate.year || date.year + 10;
+  const start = minDate ? Math.max(minDate.year, date.year - 500) : date.year - 10;
+  const end = maxDate ? Math.min(maxDate.year, date.year + 500) : date.year + 10;
 
-  return Array.from({length: end - start + 1}, (e, i) => start + i);
+  const length = end - start + 1;
+  const numbers = Array(length);
+  for (let i = 0; i < length; i++) {
+    numbers[i] = start + i;
+  }
+
+  return numbers;
 }
 
 export function nextMonthDisabled(calendar: NgbCalendar, date: NgbDate, maxDate: NgbDate) {